Have TableGen emit setSubgraphColor calls under control of a -gen-debug

flag.  Then in a debugger developers can set breakpoints at these calls
to see waht is about to be selected and what the resulting subgraph
looks like.  This really helps when debugging instruction selection.

llvm-svn: 58278

1 files changed, 45 insertions, 5 deletions

diff --git a/llvm/utils/TableGen/DAGISelEmitter.cpp b/llvm/utils/TableGen/DAGISelEmitter.cpp
index 299612977a1..82d414884b5 100644
--- a/llvm/utils/TableGen/DAGISelEmitter.cpp
+++ b/llvm/utils/TableGen/DAGISelEmitter.cpp
@@ -14,13 +14,21 @@
 #include "DAGISelEmitter.h"
 #include "Record.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/Support/CommandLine.h"
 #include "llvm/Support/Debug.h"
 #include "llvm/Support/MathExtras.h"
+#include "llvm/Support/Debug.h"
 #include "llvm/Support/Streams.h"
 #include <algorithm>
 #include <deque>
 using namespace llvm;
 
+namespace {
+  cl::opt<bool>
+  GenDebug("gen-debug", cl::desc("Generate debug code"),
+              cl::init(false));
+}
+
 //===----------------------------------------------------------------------===//
 // DAGISelEmitter Helper methods
 //
@@ -969,6 +977,10 @@ public:
         emitCode("InChains.push_back(" + ChainName + ");");
         emitCode(ChainName + " = CurDAG->getNode(ISD::TokenFactor, MVT::Other, "
                  "&InChains[0], InChains.size());");
+        if (GenDebug) {
+          emitCode("CurDAG->setSubgraphColor(" + ChainName +".getNode(), \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + ChainName +".getNode(), \"black\");");
+        }
       }
 
       // Loop over all of the operands of the instruction pattern, emitting code
@@ -1096,13 +1108,18 @@ public:
       if (II.isSimpleLoad | II.mayLoad | II.mayStore) {
         std::vector<std::string>::const_iterator mi, mie;
         for (mi = LSI.begin(), mie = LSI.end(); mi != mie; ++mi) {
-          emitCode("SDValue LSI_" + *mi + " = "
+          std::string LSIName = "LSI_" + *mi;
+          emitCode("SDValue " + LSIName + " = "
                    "CurDAG->getMemOperand(cast<MemSDNode>(" +
                    *mi + ")->getMemOperand());");
+          if (GenDebug) {
+            emitCode("CurDAG->setSubgraphColor(" + LSIName +".getNode(), \"yellow\");");
+            emitCode("CurDAG->setSubgraphColor(" + LSIName +".getNode(), \"black\");");
+          }
           if (IsVariadic)
-            emitCode("Ops" + utostr(OpsNo) + ".push_back(LSI_" + *mi + ");");
+            emitCode("Ops" + utostr(OpsNo) + ".push_back(" + LSIName + ");");
           else
-            AllOps.push_back("LSI_" + *mi);
+            AllOps.push_back(LSIName);
         }
       }
 
@@ -1269,6 +1286,18 @@ public:
       }
 
       emitCode(CodePrefix + Code + ");");
+
+      if (GenDebug) {
+        if (!isRoot) {
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +".getNode(), \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +".getNode(), \"black\");");
+        }
+        else {
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +", \"yellow\");");
+          emitCode("CurDAG->setSubgraphColor(" + NodeName +", \"black\");");
+        }
+      }
+
       for (unsigned i = 0, e = After.size(); i != e; ++i)
         emitCode(After[i]);
 
@@ -1766,8 +1795,19 @@ void DAGISelEmitter::EmitInstructionSelector(std::ostream &OS) {
 
         // Replace the emission code within selection routines with calls to the
         // emission functions.
-        CallerCode = "return Emit_" + utostr(EmitFuncNum) + CallerCode;
-        GeneratedCode.push_back(std::make_pair(false, CallerCode));
+        if (GenDebug) {
+          GeneratedCode.push_back(std::make_pair(0, "CurDAG->setSubgraphColor(N.getNode(), \"red\");"));
+        }
+        CallerCode = "SDNode *Result = Emit_" + utostr(EmitFuncNum) + CallerCode;
+        GeneratedCode.push_back(std::make_pair(3, CallerCode));
+        if (GenDebug) {
+          GeneratedCode.push_back(std::make_pair(0, "if(Result) {"));
+          GeneratedCode.push_back(std::make_pair(0, "  CurDAG->setSubgraphColor(Result, \"yellow\");"));
+          GeneratedCode.push_back(std::make_pair(0, "  CurDAG->setSubgraphColor(Result, \"black\");"));
+          GeneratedCode.push_back(std::make_pair(0, "}"));
+          //GeneratedCode.push_back(std::make_pair(0, "CurDAG->setSubgraphColor(N.getNode(), \"black\");"));
+        }
+        GeneratedCode.push_back(std::make_pair(0, "return Result;"));
       }
 
       // Print function.